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Militello in Val di Catania, Italy

Xu F.,University of Glasgow | Scullion R.A.,University of Glasgow | Yan J.,University of Glasgow | Miras H.N.,University of Glasgow | And 5 more authors.
Journal of the American Chemical Society | Year: 2011

A high-nuclearity polyoxopalladate compound, [PdII 2⊂{H7PdII 15O 10(PO4)10}]9- {PdII 17}, comprising a {Pd15} host occupied by a {Pd 2} guest and the parent pristine "empty" [H 7PdII 15O10(PVO 4)10]13- {Pd15} cluster have both been prepared and characterized by single-crystal X-ray crystallography, 31P NMR, CSI-MS, and XPS. The encapsulated {Pd2} has a short PdII-PdII distance within the {Pd15} host. Solution studies indicate that the empty host and filled guest complex are in equilibrium with each other, and UV titrations revealed a binding constant of ca. 103 for the guest PdII ions, with a binding stoichiometry of almost 2. © 2011 American Chemical Society.

Russo P.,University of Catania | Compagnini G.,University of Catania | Musumeci C.,Superlab Consorzio Catania Ricerche | Pignataro B.,University of Palermo
Journal of Nanoscience and Nanotechnology | Year: 2012

Graphene is a two dimensional building block for carbon allotropes of many other dimensionality and shows remarkable electronic and optical properties that attract enormous interest. In order to make graphene useful for real technology, a control of its electronic and mechanical properties is a must. In this respect, a crucial step for the use of graphene layers in device fabrication is the deposition onto suitable substrates, understanding the interaction with them. Micromechanical cleavage of graphite has been used to produce high-quality graphene sheets. The aim of this work is to study the strain effects induced in graphene by the deposition process using Raman spectroscopy and scanning force microscopy. The study reveals that this deposition method randomly produces strained and unstrained graphene sheets, which can be distinguished through an appropriate analysis of the Raman spectra using polarized incident light. We have also observed that the induced strain can be partially restored under thermal treatments. Copyright © 2012 American Scientific Publishers.

Musumeci C.,Superlab Consorzio Catania Ricerche | Rosnes M.H.,University of Glasgow | Giannazzo F.,CNR Institute for Microelectronics and Microsystems | Symes M.D.,University of Glasgow | And 2 more authors.
ACS Nano | Year: 2011

Utilizing Langmuir-Blodgett deposition and scanning probe microscopy, we have investigated the extent to which cations alter the self-assembly processes of hybrid polyoxometalates (POMs) on surfaces. The well-defined 2D hexagonal nanostructures obtained were extensively characterized and their properties were studied, and this has revealed fascinating dielectric behavior and reversible capacitive properties. The nanostructures are extremely stable under ambient conditions, and yet exhibit fascinating self-patterning upon heating. These findings present POMs as effective smart nanodielectrics and open up a new field for future POM applications. © 2011 American Chemical Society.

Rosnes M.H.,University of Glasgow | Musumeci C.,Superlab Consorzio Catania Ricerche | Pradeep C.P.,University of Glasgow | Mathieson J.S.,University of Glasgow | And 5 more authors.
Journal of the American Chemical Society | Year: 2010

Three organic-inorganic hybrid Mn-Anderson polyoxometalates (POMs), with both symmetrical and asymmetrical appended groups, have been synthesized, identified using electrospray mass spectrometry, and isolated using an approach that allows the three AA, BB, and AB compounds to be structurally characterized. Investigation of the self-assembly of the hybrids on hydrophilic surfaces reveals the formation of nanofibres with characteristics that reflect the nature of the substitution of the POM yielding a route to the programmed assembly of anisotropic hybrid nanostructures. © 2010 American Chemical Society.

Musumeci C.,Superlab Consorzio Catania Ricerche | Luzio A.,University of Palermo | Pradeep C.P.,University of Glasgow | Miras H.N.,University of Glasgow | And 5 more authors.
Journal of Physical Chemistry C | Year: 2011

The exploration of the self-organization of a range of the polyoxometalate-based molecular structures reveals a diverse range of surface patterns and morphologies on solid substrates of technological interest, including methylated and hydroxylated silicon surfaces (namely, SiCH3 and SiOH). By exploiting the interplay between the intrinsic molecular properties and the surface chemistry as well as dynamic spatiotemporal phenomena (e.g., dewetting), we show that these systems can yield 0D, 2D, and 3D architectures via solution deposition at the solid surface, including nanodots, discs, lamellas, porous networks, and layer-by-layer assemblies. In general, we observed that layer-by-layer growth is a common feature on low surface energy SiCH3. In addition, the polyoxometalate derived architectures are able to effectively modulate the drop spreading dynamics on high surface energy SiOH, so that dewetting induces the formation of nanodots from dilute solutions of the precursor POM hybrid, whereas using high concentration results in the formation of complex architectures whose shape depends on the molecular structure of the POM-based building block utilized. Finally, we show that hybrid POM derivatives with one or more functional moieties can be organized in an ordered fashion, thus yielding interesting model systems for the assembly of POM-based multifunctional nanostructures on surfaces. © 2011 American Chemical Society.

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